Changeset 2e5c4b9 in clfs-embedded

Timestamp:

Sep 18, 2012, 5:19:15 AM (12 years ago)

Author:

Andrew Bradford <andrew@…>

Branches:

master

Children:

c31ae75

Parents:

8ffc08dd

Message:

cross-tools/arm/abi: Provide recommendations on ABI

ABI selection for ARM is often confusing and the -support list often
has people reporting that they have difficulty selecting the best ABI
for their board.

Add some clarification and recommendations. Move aapcs-linux and
apcs-gnu to the top of the table as those are really the only two
choices that should be used.

Signed-off-by: Andrew Bradford <andrew@…>

File:

• BOOK/cross-tools/arm/abi.xml (modified) (4 diffs)

BOOK/cross-tools/arm/abi.xml

@@ -13 +13 @@
   <para os="a">On the ARM architecture, there are two major ABI types to choose
   from: EABI and OABI.  There is also a Thumb ABI and an Intel IWMMX specific
-  ABI.</para>
+  ABI but these are generally not recommended for most uses.</para>
 
   <para os="b">The EABI (Embedded ABI) is newer and supports additional
@@ -19 +19 @@
   but is only compatible with ARMv4t and newer cores.  The EABI has
   sub-ABIs of: aapcs-linux and aapcs.  aapcs-linux has standard Linux 4 byte
-  enums while aapcs has variable length enums.</para>
+  enums while aapcs has variable length enums.  aapcs-linux is recommended over
+  aapcs.</para>
 
   <para os="c">The OABI (old ABI) is called apcs-gnu and supports ARMv4 and 
-  older cores.</para>
+  older cores.  Generally the OABI is not used by modern ARM processors.</para>
 
   <xi:include xmlns:xi="http://www.w3.org/2003/XInclude"
@@ -56 +57 @@
       <tbody>
         <row>
+          <entry>aapcs-linux</entry>
+          <entry>aapcs-linux</entry>
+          <entry>Recommended for EABI. Standard Linux 32 bit (int) enums</entry>
+        </row>
+        <row>
           <entry>apcs-gnu</entry>
           <entry>apcs-gnu</entry>
-          <entry>OABI</entry>
+          <entry>Recommended for OABI</entry>
         </row>
         <row>
@@ -69 +75 @@
           <entry>aapcs</entry>
           <entry>EABI w/ variable size enums</entry>
-        </row>
-        <row>
-          <entry>aapcs-linux</entry>
-          <entry>aapcs-linux</entry>
-          <entry>EABI w/ standard Linux 32 bit (int) enums</entry>
         </row>
         <row>